Additive effect enhanced hydrogen peroxide disinfection method and apparatus

ABSTRACT

A method which enhances a disinfection process by obtaining an additive effect from energy and byproducts of the decomposition process. Also disclosed are contact lens disinfecting systems, wherein the systems are configured to create the desirable elevated pressure, oxygen saturation and sustained peroxide concentration conditions within a contact lens holding and reaction chamber, in order to enhance disinfection by additive effect. The systems are configured to provide that an elevated pressure is maintained in the reaction chamber before venting occurs.

RELATED APPLICATIONS Priority Claim

This application claims the benefit of the following United StatesProvisional Applications, all of which are incorporated herein byreference in their entirety: U.S. Provisional Application Ser. No.61/160,488, filed Mar. 16, 2009; U.S. Provisional Application Ser. No.61/162,881, filed Mar. 24, 2009; U.S. Provisional Application Ser. No.61/166,932, filed Apr. 6, 2009; and U.S. Provisional Application Ser.No. 61/171,175, filed Apr. 21, 2009.

BACKGROUND

The present invention generally relates to methods and apparatus forcontrolling the decomposition of a solution using a catalyzing agent,and more specifically relates to a method and apparatus for controllingand enhancing a disinfection process by additive effect.

The present invention relates to an improved disinfection method andapparatus which utilizes, for example, hydrogen peroxide solution and acatalyzing agent to facilitate controlled decomposition of the hydrogenperoxide within a sealed reaction chamber containing an object to bedisinfected, such as contact lenses, wherein the solution, thedecomposition catalyzing agent, the resulting energy, and byproducts ofdecomposition are employed to control and enhance the disinfectionprocess by additive effect.

While the method disclosed herein may be utilized, for example, todisinfect contact lenses, particularly soft contact lenses, the methodmay also be suitable to disinfect other types of items, for examplelarger items, such as non-sterile medical or dental appliances and thelike, within a reaction chamber appropriately scaled to size. As such,while the present disclosure focuses on using the method (and associatedapparatus) to disinfect contact lenses using hydrogen peroxide, itshould be understood that the method can be used in other disinfectingapplications.

Hydrogen peroxide is unstable and eventually decomposes(disproportionates) into water and oxygen over time. The decompositionoccurs more quickly if the hydrogen peroxide is, for example, subjectedto temperature extremes, exposed to ultraviolet light, or introduced toa catalyzing agent. The decomposition rate is also affected by itspercentage of concentration, its pH, and the presence of impurities andstabilizers. The decomposition process is exothermic in nature and whena catalyzing agent has been introduced to the hydrogen peroxide, evolvedthermal energy and oxygen can accelerate the process by several meansthat increase molecular contact opportunities with the catalyzing agent.The means include creation of thermally inspired convection, mechanicalmixing resulting from the stirring effect of rising oxygen bubbles, aswell as increased molecular motion which lowers the energy threshold fordecomposition.

Hydrogen peroxide is a larger molecule than water with a specificgravity of 1.443 and a viscosity of 1.245 cP at 20 degrees Celsius,compared to water which has a viscosity of 1.003 cP at 20 degreesCelsius. Nevertheless, each is entirely miscible with the other,allowing a limitless variety of concentration levels to be tailored tosuit various applications. Hydrogen peroxide solutions formulated fordisinfection may contain surfactants, and are often pH-modified andchemically-stabilized in order to assure reasonable shelf life andpotency at the time of use. Hydrogen peroxide formulated fordisinfection of contact lenses, for example, is generally supplied at aconcentration of no less than 3.0%, and may range up to 4.0% in order toassure that a minimum concentration of 3.0% is available fordisinfection.

While more highly concentrated solutions would be more potent andeffective against pathogens, the use of more highly concentratedsolutions has generally not been pursued for contact lens care use. Thisis due to the strong oxidizing nature of hydrogen peroxide, and thedamaging effects such higher concentrations could have upon accidental,full strength contact with sensitive ocular tissue.

Catalysts that facilitate decomposition of hydrogen peroxide includemost of the transition metals, manganese dioxide, silver and the enzymecatalase. Quite commonly in connection with single step contact lensdisinfection systems, platinum is introduced to the solution in the formof a surface coating on a polymeric support structure. Catalystsfunction by changing the energy pathway for a chemical reaction. FIG. 1provides a graph which compares the energy associated with activatingwithout a catalyst (line 10) to the energy associated with activatingwith a catalyst (line 12). As indicated, when introduced to hydrogenperoxide, a catalyst serves to lower the activation energy required toinitiate decomposition of the hydrogen peroxide under ambient conditionsin which it was otherwise stable.

The combination of solution temperature, exothermally-generated heat,thermally-inspired convection, mechanical stirring from evolving oxygenbubbles, dilution resulting from disproportionation, dissolved gas inthe solution, and changes in ambient pressure has been found to impactthe rate at which the catalyzed reaction progresses. In an openenvironment such as that provided by a typical commercially-availablehydrogen peroxide disinfection cup system for contact lenses, forexample the AO SEPT system (as shown in FIG. 2, with the overall systembeing identified with reference numeral 13) offered by Ciba Vision,contact lenses are introduced to 10 milliliters of the hydrogen peroxidesolution essentially simultaneously with the catalyst, and evolvedoxygen from the reaction is subsequently vented off through ahydrophobic membrane or one way valve (indicated with reference numeral14 in FIG. 2) in the cap (indicated with reference numeral 15 in FIG.2). As shown in FIG. 3, with this type of system, solution concentrationresulting from the catalyzed reaction declines rather rapidly to about0.1%, whereupon six to eight hours are required before the concentrationof the solution bath has been reduced to a level that is safe for adisinfected lens to be inserted in the eye without risk of ocularirritation to the user.

Disinfection of contact lenses is regularly practiced by lens wearers inorder to eliminate a variety of environmentally ubiquitous organismsknown to be found on contaminated lenses. The organisms at issueinclude, but are not limited to, various pathogenic strains ofStaphylococcus, Pseudomonas, E. Coli, Acanthamoeba, and the like.Acanthamoeba is an opportunistic pathogen associated with a potentiallyblinding infection of the cornea termed Acanthamoeba keratitis. Amongthe general population, contact lens wearers are believed to be most atrisk to this organism, accounting for more than 95% of reported cases ofthe ocular infection. A particularly insidious organism, Acanthamoebacan transition from active trophozoite to a dormant, more resistantencysted stage when exposed to conditions of starvation, desiccation,and changes in pH and temperature. Once encysted, this organism'sresistance to biocides results largely from the physical barrier of itscyst walls rather than as a consequence of metabolic dormancy. The majorcomponents of the cyst's walls are acid-resistant proteins andcellulose, with the outer wall, or exocyst, composed primarily ofprotein and the inner endocyst comprised of over 30% cellulose. Althoughremarkably resistant to chlorine-bearing disinfectants and evenhydrochloric acid, encysted Acanthamoeba is subject to destruction byexposure to hydrogen peroxide.

Under standard ambient conditions, the method by which hydrogen peroxidedestroys pathogens is through oxidation resulting in denaturation of theorganism's proteins. One option to deal with heavily contaminated lensesor resistant organisms, such as Acanthamoeba, would be to start with amore highly concentrated solution, but there are undesirable user risksassociated with that approach. Some of these risks have already beendiscussed hereinabove.

A more attractive option would be to slow the decomposition process inorder to maintain a higher concentration of hydrogen peroxide for alonger period of time before finally reducing the concentration to anocularly comfortable level. With such an approach, more heavilycontaminated lenses could therefore be disinfected, and resistantorganisms could be better dealt with using solutions that havecommonly-accepted concentrations. Unfortunately, present daydisinfection systems are limited by the reaction rate necessary toobtain irritation-free disinfected lenses at the end of a reasonable 6to 8 hour overnight wait period. This results from a balance that hashistorically been struck between the volume of peroxide solution, a safeand practical starting concentration level for the peroxide, and thesize of catalyst (such as platinum) necessary to assure adequatedecomposition in use. Regarding catalyst size, typically 94 squaremillimeters to 141 square millimeters of catalyst surface area isallocated for each milliliter of 3.0% to 4.0% hydrogen peroxidesolution. Although an undersized catalyst would certainly slow thedecomposition process, using an undersized catalyst may result in thelens solution not reaching user comfort levels within a reasonable timeperiod, since the significance of catalyst surface area actuallyincreases as the amount of released energy and solution concentrationdeclines. Additionally, methods (such as is disclosed in U.S. Pat. No.5,468,448) of slowing decomposition by using buoyant catalysts that havecontact areas which increase as they sink from loss of attached bubbleshave proven too difficult to commercialize reliably.

OBJECTS AND SUMMARY

An object of an embodiment of the present invention is to provide animproved disinfection method.

Another object of an embodiment of the present invention is to providean apparatus which can be used to practice the method.

Briefly, a specific embodiment of the present invention provides amethod which can be used to disinfect, for example, contact lenses usinghydrogen peroxide and a catalyst. The method provides that once thecatalyst is introduced to the hydrogen peroxide in a reaction chamber,such as in a contact lens case, and the reaction chamber is sealed, thehydrostatic pressure within the reaction chamber is allowed to reach arelatively high level before venting takes place. Allowing thehydrostatic pressure within the reaction chamber to achieve a relativelyhigh level before venting provides for a hydrogen peroxide disinfectionprocess which is enhanced by additive affect.

BRIEF DESCRIPTION OF THE DRAWINGS

The organization and manner of the structure and operation of theinvention, together with further objects and advantages thereof, maybest be understood by reference to the following description, taken inconnection with the accompanying drawing, wherein:

FIG. 1 is a graph which effectively compares the energy associated withactivating without a catalyst to the energy associated with activatingwith a catalyst;

FIG. 2 is a perspective view of a prior art contact lens disinfectioncup system, specifically the AO SEPT system offered by Ciba Vision;

FIG. 3 is a graph which indicates the change in concentration of ahydrogen peroxide solution over time, when the cup system shown in FIG.2 is used to disinfect contact lenses;

FIG. 4 is a graph which indicates the change in pressure over time,comparing the use of a catalyst having a given surface area, to the useof a catalyst having twice the surface area;

FIG. 5 is a graph which is similar to the graph shown FIG. 1, but whichalso plots the energy associated with activating at an elevatedpressure;

FIG. 6 is a graph which indicates the change in peroxide concentrationover time, comparing a vented system to a high pressure system;

FIGS. 7 and 8 are cross-sectional views of a contact lens disinfectingsystem, wherein the system is configured to create desirable elevatedpressure, oxygen saturation, sustained peroxide concentrationconditions, and rapid decompression, in order to enhance disinfection byadditive effect;

FIG. 9 is a graph which is similar to the graph shown in FIG. 4, butgoes on to show the pressure decreasing once venting occurs;

FIGS. 10 and 11 are cross-sectional views of a contact lens disinfectingsystem which is in accordance with an alternative embodiment of thepresent invention;

FIG. 12 is a perspective view of a spring member component of thecontact lens disinfecting system shown in FIGS. 10 and 11;

FIG. 13 is a graph which shows how the beam strength of the springmember of FIGS. 10-12 changes based on the amount of deflection;

FIG. 14 is a graph which shows the change in pressure over time duringthe disinfection process, when the contact lens disinfecting systemshown in FIGS. 10 and 11 is used;

FIGS. 15 and 16 are cross-sectional views of a contact lens disinfectingsystem which is in accordance with yet another embodiment of the presentinvention;

FIGS. 17 and 18 are cross-sectional views of a contact lens disinfectingsystem which is in accordance with another embodiment of the presentinvention;

FIGS. 19 and 20 are side cross-sectional views of a portion of thecontact lens disinfecting system which is shown in FIGS. 17 and 18;

FIG. 21 is a graph which shows the change in pressure over time duringthe disinfection process, when the contact lens disinfecting systemshown in FIGS. 17 and 18 is used;

FIGS. 22 and 23 are cross-sectional views of a contact lens disinfectingsystem which is in accordance with another embodiment of the presentinvention;

FIG. 24 is a graph which shows the change in pressure over time duringthe disinfection process, when the contact lens disinfecting systemshown in FIGS. 22 and 23 is used;

FIGS. 25 and 26 are cross-sectional views of a contact lens disinfectingsystem which is in accordance with another embodiment of the presentinvention; and

FIGS. 27 and 28 are cross-sectional views of a contact lens disinfectingsystem which is in accordance with still yet another embodiment of thepresent invention.

DESCRIPTION

The inventions disclosed herein are susceptible to embodiment in manydifferent forms. However, specific embodiments are shown in the drawingsand described in detail hereinbelow. The present disclosure is to beconsidered an example of the principles of the invention, and is notintended to limit the invention to the specific embodiments which areillustrated and described herein.

The method disclosed herein enhances the disinfection process byobtaining an additive effect from energy and byproducts of thedecomposition process. Useful energy is available during thecatalytically-inspired disproportionation of hydrogen peroxide solutionin the form of heat and expansion of evolved oxygen molecules.

As will be described more fully later hereinbelow, FIGS. 7 and 8illustrate a contact lens disinfection system which is in accordancewith an embodiment of the present invention, and is configured to allowinternal pressure to become somewhat significant before venting takesplace. FIG. 4 is a graph which indicates the change in internal pressureover time, when a system such as is shown in FIGS. 7 and 8 is employed,comparing the use of a catalyst having a given surface area (representedin FIG. 4 by the curve identified with reference numeral 16), to the useof a catalyst having twice the surface area (represented in FIG. 4 bythe curve identified with reference numeral 18). As shown, containmentof the liberated oxygen from 10 milliliters of solution within areaction chamber having 4 cc of head space, a volume similar to thetypical contact lens cup discussed above (and illustrated in FIG. 2),has the potential to generate approximately 186 p.s.i. pressure withinone half hour following introduction of a catalyst having 948 squaremillimeters of surface area, and as much as 366 p.s.i. in one half hourupon introduction of a catalyst having twice that surface area. As canbe seen in FIG. 6, either catalyst has the ability to raise internalpressures to 100 p.s.i. within 9 minutes at which time the peroxideconcentration shown in FIG. 6, line 24 is over 4 times greater than thatof the vented system (line 22).

Although a catalyst having more than 94 to 141 square millimeters ofsurface area for each cubic centimeter of solution would serve todecrease hydrogen peroxide solution concentration too quickly foreffective disinfection in a vented system, introducing such a catalystinto a closed system has been found to offer improved disinfectionpossibilities not otherwise available. Specifically, larger catalystsprovide a higher initial rate of activity which, in turn, delivers aquicker pressure rise to high hydrostatic pressure within the system. Alarger catalyst provides for an increased surface area to fluid volumeratio, thereby providing a larger catalyst that is more effective inbringing end reaction concentrations to lower, ocularly safe levels.

High hydrostatic pressure resulting from containment of evolving oxygenalso increases the amount of dissolved oxygen that can be absorbedwithin the solution allowing it to become saturated with the gas. Forexample, at 300 p.s.i. and 23 degrees Celsius, approximately 0.0122milliliters of oxygen dissolve into a 10 milliliter solution bath. FIG.5 provides a graph which not only compares the energy associated withactivating without a catalyst (line 10) to the energy associated withactivating with a catalyst (line 12), but also plots the energyassociated with activating at an elevated pressure (line 20).

As initially high hydrostatic pressure tends to slow the reaction byraising the level of activation energy required for decomposition,oxygen dissolving into instead of rising from the solution plays a partas well. Viewed strictly from a mechanical perspective, althoughdiffusion ultimately will balance the concentration of solution within acontainer over time, hydrogen peroxide has been found to be subject toshort term stratification within a solution bath when decomposition isinitiated by a catalytic structure and those oxygen molecules notentering into solution under pressure form bubbles of much smaller sizeleading to decreased mechanical mixing of the solution bath as they riseto the surface.

Additive effects to enhance the disinfection process are thereforeavailable when energy and byproducts yielded by the disproportionationreaction are harnessed and incorporated back into the process. Increasedhydrostatic pressure created by expanding oxygen within the disinfectingchamber allows more evolved oxygen to dissolve into solution. As aresult, less mixing occurs from increasingly smaller and fewer risinggas bubbles, and the activation energy requirement for decompositionincreases. This works to retard the rate at which decomposition occursin order to sustain a significantly higher concentration of solution fora longer period of time. FIG. 6 compares peroxide concentration as itchanges over time, in a vented system (i.e., under typical atmosphericconditions) (line 22) versus a high pressure system (i.e., under typicalatmospheric conditions) (line 24). As shown, under elevated pressure theperoxide concentration is 2.4 times that of the vented system at 5minutes into the reaction (i.e., after 5 minutes of elapsed reactiontime), 4.7 times that of the vented system at 10 minutes, 6.8 times thatof the vented system at 20 minutes, and 6.4 times that of the ventedsystem at 30 minutes.

When employing high pressure from contained, expanding, evolved oxygenin order to assist a hydrogen peroxide solution in obtaining greaterpenetration and oxidative potential, the high hydrostatic pressureconditions thereby created can also be leveraged to exploit the naturaldynamic equilibrium of pathogens, as diffusion allows for an elevatedoxygen condition to be created within the organism under oxygensaturated conditions sustained by the pressurized solution bath. Afurther additive effect can thereafter be realized as a consequence ofintroducing a subsequent rapid decompression from the high pressurecondition to elicit release of dissolved oxygen from solution observableas an effervescence of the gas, and thereby cause expansion of excessabsorbed oxygen within the pathogen to further stress the organism'scell membrane undergoing oxidative denaturation from hydrogen peroxideexposure. This mechanism compliments the destructive effects ofoxidative denaturation upon the pathogen's proteins. Followingdecompression, with high pressure having been relieved, the catalyticreaction is therefore allowed to resume at a faster, low pressure pacein order to assure that decomposition has been completed to anacceptable level within the desired 6 to 8 hour time span.

FIGS. 7 and 8 illustrate a contact lens disinfecting system 40, whereinthe system is in accordance with an embodiment of the present invention,and is configured to create the desirable elevated pressure, oxygensaturation and sustained peroxide concentration conditions within itscontact lens holding and reaction chamber, in order to enhancedisinfection by additive effect as disclosed hereinabove.

As shown in FIGS. 7 and 8, the contact lens disinfecting system 40comprises a cup 42 and a cap assembly 44 which is configured tothreadably engage the top 46 of the cup 42. The cup 42 is conventionalin that it is generally cylindrical and provides a reaction chamber 48therein for disinfecting contact lenses.

The cap assembly 44 includes a valve body 50, and a stem 52 is attachedto and hermetically sealed to the valve body 50. A catalyst 54(conventional with regard to composition), sized to complete thereaction within an appropriate time, is affixed to the bottom 56 of thestem 52. Additionally, contact lens retaining baskets 58 are disposed onthe stem 52. The retaining baskets 58 are configured to pivot open andclosed, in order to receive contact lenses, and maintain the contactlenses in a space 60 which is provided between the stem 52 and theretaining baskets 58. The stem 52 and retaining baskets 58 may beconventional, such as described in either U.S. Pat. No. 4,200,187 orU.S. Pat. No. 4,750,610, both of which are incorporated herein byreference in their entirety. A sealing member 62 is provided on the stem52, for sealing against an internal wall 64 of the cup 42.

As discussed, the cap assembly 44 includes a valve body 50. The valvebody 50 preferably consists of a single, multi-walled body such as isindicated in FIGS. 7 and 8, and is configured to threadably engage thetop 46 of the cup 42. The valve body 50 provides a passage 66, anaperture 68 leads to the passage 66, and a breathable membrane 70 isprovided at the end 72 of the passage 66, on the valve body 50. Thebreathable membrane 70 may be composed of, for example, either a filtermaterial or a hydrophobic filtering material having a pore size ofpreferably one half micron but no more than two microns.

The valve body 50 also includes a receptacle 74 which has a plunger 76disposed therein. The plunger 76 can take many forms, but one preferredstructure of the plunger 76 provides that the plunger 76 consists of aplastic body having a piston 78, formed of an elastomeric material,molded onto the end of the plastic body. As such, the piston 78effectively defines the end 80 of the plunger 76. The plunger 76 isconfigured to traverse within the receptacle 74 of the valve body 50,such that the piston 78 can traverse relative to a piston cylinder area82.

The piston 78 is configured to provide a first plunger seal 84 and asecond plunger seal 86. When the plunger 76 is in the position shown inFIG. 7, the first and second plunger seals 84, 86 seal againstrespective internal walls 88, 90 of the valve body 50, thereby providingthat the system 40 is sealed. However, when the plunger 76 moves to theposition shown in FIG. 8, the first plunger seal 84 slides out ofcontact with the internal wall 88 of the valve body 50 (in the pistoncylinder area 82), thereby providing that the reaction chamber 48 canvent, as will be described in more detail later hereinbelow.

In use, approximately 10 milliliters of hydrogen peroxide solution 92 ispoured into the cup 42, the retaining baskets 58 on the stem 52 arepivoted open, contact lenses are placed onto the stem 52, and then theretaining baskets 58 are pivoted closed in order to retain the contactlenses in space 60. Finally, the stem 52 is inserted into the cup 42,and the cap assembly 44 is threaded onto the top 46 of the cup 42.Preferably, the cup 42 is sized such that when the cap assembly 44 isthreaded onto the top 46 of the cup 42, with 10 milliliters of hydrogenperoxide 92 being contained in the cup 42, there remains 4 cc's ofheadspace 98 above the hydrogen peroxide 92, for containment of oxygengas which evolves during the disinfection process. While providing 4cc's of headspace is one possibility, the volume of the headspace 98 canbe varied as can the surface area of the catalyst 54, in order toachieve a desired internal pressure to control the reaction aspreviously discussed.

The catalytically-stimulated disproportionation reaction begins whencontact lenses, contained within space 60 between the stem 52 andretaining baskets 58, are immersed in the hydrogen peroxide solution 92simultaneously with introduction of the catalyst 54 into the hydrogenperoxide solution 92. Thereafter, disinfection solution and pressurewithin the system is contained between the cup 42 and the cap assembly44 via the sealing member 62 being sealed against the internal wall 64of the cup 42, and via the first plunger seal 84 being sealed againstwall 88, as shown in FIG. 7.

A detent ball 100 is contained in the valve body 50 and is biased intocontact with the plunger 76 by a spring member 102. Specifically, whenthe plunger 76 is in the sealing position as shown in FIG. 7, the detentball 100 engages a receiving groove 104 which is provided on the plunger76. From a starting position as shown in FIG. 7, longitudinal movementof the plunger 76 within the receptacle 74 is controlled by the detentball 100 residing within the receiving groove 104 of the plunger 76. Thedetent ball 100 is held against the plunger 76 by the spring elementmember 102 which is appropriately configured to detain its movementuntil sufficient force is exerted upon piston 78 (in the direction ofarrow 106 in FIG. 7) to push the detent ball 100 aside, allowing theplunger 76 to traverse within the receptacle 74 from the position shownin FIG. 7 to the position shown in FIG. 8. Although a ball-shaped detentis shown in FIGS. 7 and 8, a similar function could be achieved using adetent which is shaped differently than a ball, such as anelongated-shaped detent. Regardless, the detent 100 functions to providethat the plunger 76 can move from its sealing position shown in FIG. 7,to its venting position shown in FIG. 8, only upon the reaction chamber46 reaching a substantial high pressure condition. When the plunger 76is in the position shown in FIG. 7, the plunger seal 84 effectivelycontains the evolved gas and prevents it from passing upward the alongplunger 76. Once the pressure in the reaction chamber 46 increases to asufficient level, the plunger 76 moves upward in the receptacle 74 asshown in FIG. 8, allowing the reaction chamber 46 to vent.

In addition to including the valve body 50, the cap assembly 44 alsoincludes a cap 108 which is engaged with the valve body 50. The cap 108is generally cylindrical and retains the valve body 50 via, for example,a circumferential lip 110. Specifically, the cap 108 is mounted on thevalve body 50 such that the cap 108 is rotatable relative to the valvebody 50. This will be described more fully later hereinbelow.Regardless, the cap 108 has a post 112 therein, and longitudinal motionof the plunger 76 within the receptacle 74 is limited by a top 114 ofthe plunger 76 contacting the post 112, as shown in FIG. 8.

Once the piston 78 has moved sufficiently within the piston cylinderarea 82, the piston 78 enters a transition section 116. The transitionsection 116 is configured to gradually reduce seal contact of theplunger seal 84 against the internal wall 88 of the piston cylinder area82, and therefore initiates both leakage of oxygen gas from within theheadspace 98 and effervescence of dissolved oxygen into headspace 98,past the piston 78, into the transition section 116, through theaperture 68 into passage 66, through the breathable membrane 70, intothe atmosphere. This fluid path is indicated with arrows 118 in FIG. 8.

As described above, the breathable membrane 70 may be composed of eithera filter material or a hydrophobic filtering material having a pore sizeof preferably one half micron but no more than two microns. Although notessential to the reaction of the peroxide, the breathable membrane 70provides a barrier to entrance of undesirable organisms after theperoxide solution 92 has been catalytically decomposed.

Decompression provides a further additive effect to the disinfectionprocess when oxygen occupying the headspace 98 is allowed to escape bymovement of the piston 78 and saturated oxygen within the hydrogenperoxide disinfection solution effervesces from it, thereby allowingpressure in the headspace 98 to drop to a point slightly above theatmospheric ambient much more quickly than a pathogenic organism couldadjust to maintain dynamic equilibrium. During the pressurization anddecompression phases of the process, including venting to atmosphere,pressure within the headspace 98 rises and falls in a manner as shown inFIG. 9 (depending on which size catalyst 54 is used, wherein asdiscussed above in connection with FIG. 4, the curve identified withreference numeral 16 relates to the use of a catalyst having a givensurface area, and the curve identified with reference numeral 18 relatesto the use of a catalyst having twice the surface area). After highpressure has been relieved within the system 40, the rate ofcatalytically-inspired disproportionation of the hydrogen peroxidesolution 92 increases beyond that just prior to pressure relief as theactivation energy level is lowered. Mixing currents are also generatedas oxygen boils from the solution 92, and these resulting currentsinitially speed the catalytic decomposition by disturbing stratificationto bring more peroxide molecules into contact with the catalyst 54.Oxygen continues to be evolved as final decomposition of the solution 92lowers peroxide concentration toward an ocularly safe level for use ofthe lenses disinfected within.

As discussed above, the cap 108 is mounted on the valve body 50 suchthat the cap 108 is rotatable relative to the valve body 50. As shown inFIGS. 7 and 8, preferably the upper surface 120 of the valve body 50provides a castellated structure 122 which is configured to mate withcorresponding castellated structure 124 which is provided inside the cap108. A spring element 126 is preferably provided inside the cap assembly44, between the cap 108 and the valve body 50. Specifically, one end 128of the spring element 126 preferably engages a shoulder 130 which isprovided on the valve body 50, and the other end 132 of the springelement 126 preferably engages an inside surface 134 of the cap 108. Assuch, the castellated structure 124 which is provided inside the cap 108is biased (via the spring element 126) out of engagement with thecorresponding castellated structure 122 which is provided on the topsurface 120 of the valve body 50.

Once the disinfection process has been completed, after 6 to 8 hours forexample, the cap 108 which is ordinarily free to rotate relative to thevalve body 50, must be pressed downward to compress the spring element126, in order to engage the castellated structure 124 on the insidesurface 134 of the cap 108 with the castellated structure 122 on valvebody 50. Once the cap 108 is pressed down such that the two castellatedstructures 122, 124 are engaged with each other, rotation of the cap 108in a counter-clockwise direction causes the cap assembly 44 to unscrewfrom its threaded engagement with the top 46 of the cup 42.

Pushing the cap 108 downward to unscrew the cap assembly 44 also causesthe post 112 of the cap 108 to push down on the plunger 76, causing theplunger 76 to shift downward in the receptacle 74, and allowing thedetent ball 100 to re-engage the receiving groove 104 of the plunger 76.The translation of the plunger 76 downward also causes the piston seal84 to re-seal with the internal wall 88 of the piston cylinder area 82.As such, the device 40 is thereafter prepared for the next disinfectionprocess.

Preferably, sufficient threads 136, 138 are provided on the cup 42 andthe cap assembly 44, respectively, to allow the sealing member 62 on thestem 52 to pass a chamfer 140 which is provided at the top 46 of the cup42, in order to relieve any residual pressure that may be present priorto final unscrewing of the cap assembly 44 from the cup 42. Conversely,during installation of the cap assembly 44, sufficient thread engagementis provided before the sealing member 62 on the stem 52 passes below thechamfer 140, in order to assure that adequate structure is engaged forcontainment of pressure generated during disinfection.

Pressing the cap 108 down upon the valve body 50 to re-engage the matingcastellation structures 122, 124 for installation of the cap assembly 44to the cup 42, as would be done by a user to initiate the nextdisinfection cycle, also serves to assure that the plunger 76 reseatsinto its proper position before the next cycle is started. Uponthreading the cap assembly 44 onto the cup 42, and upon releasing thecap 108, the system arrives at the condition shown in FIG. 7, ready forthe next disinfection cycle.

As discussed, the contact lens disinfecting system 40 shown in FIGS. 7and 8 is configured to enhance the disinfection process by additiveeffect. Of course, other embodiments (such as embodiments employingother cap assembly designs, for example) are entirely possible in orderto implement the additive affect enhanced disinfection process describedhereinabove.

For example, FIGS. 10 and 11 are cross-sectional views of a contact lensdisinfecting system 40 a which is in accordance with an alternativeembodiment of the present invention. Like the contact lens disinfectionsystem 40 shown in FIGS. 7 and 8, the contact lens disinfection system40 a shown in FIGS. 10 and 11 is configured to create the desirableelevated pressure, oxygen saturation and sustained peroxideconcentration conditions within its contact lens holding and reactionchamber, in order to enhance disinfection by additive effect asdisclosed hereinabove.

The structure and operation of the contact lens disinfection system 40 ashown in FIGS. 10 and 11 is similar to the contact lens disinfectingsystem 40 shown in FIGS. 7 and 8 in many respects. As such, identicalreference numerals are used to identify identical parts. For example,much like the contact lens disinfecting system 40 shown in FIGS. 7 and8, the contact lens disinfection system 40 a shown in FIGS. 10 and 11includes a cup 42 and a cap assembly 44 a which is configured tothreadably engage the top 46 of the cup 42, and the cup 42 isconventional in that it is generally cylindrical and provides a reactionchamber 48 therein for disinfecting contact lenses.

The cap assembly 44 a comprises a cap 108 a which is affixed to a valvebody 50 a. The valve body 50 a is configured to threadably engage thetop 46 of the cup 42, and a stem 52 a is attached to and hermeticallysealed to the valve body 50 a. A catalyst 54 (conventional with regardto composition), sized to complete the reaction within an appropriatetime, is affixed to the bottom 56 of the stem 52 a. Additionally,contact lens retaining baskets 58 are disposed on the stem 52 a. Theretaining baskets 58 are configured to pivot open and closed, in orderto receive contact lenses, and maintain the contact lenses in a space 60which is provided between the stem 52 a and the retaining baskets 58. Asealing member 62 is provided on the stem 52 a, for sealing against aninternal wall 64 of the cup 42.

As described above, the contact lens disinfecting system 40 shown inFIGS. 7 and 8 provides that there is a passage 66 in the valve body 50,and an aperture 68 leads to the passage 66, to provide a fluid path forventing. In contrast, the contact lens disinfecting system 40 a shown inFIGS. 10 and 11 provides a fluid passage 200 between a top 202 of thestem 52 a and the valve body 50 a.

The cap assembly 44 a includes a plunger 204, and a bottom part 206 ofthe plunger 204 defines a piston 208. The piston 208 may be generallycylindrical having a domed end surface 210. The piston 208 includes aventing feature 212, such as a longitudinal slot 214 along the piston208. While a longitudinal slot 214 is shown in FIGS. 10 and 11, theventing feature 212 may take other forms, such as a flat along the sideof the piston 208, or a reduced diameter section along the piston 208,for example. Regardless, the venting feature 212 provides forcommunication with the passage 200 for venting the reaction chamber 48,as will be described more fully later hereinbelow.

A piston seal 216 is provided in a receiving groove 218 between the stem52 a and the valve body 50 a, and a plunger seal 220 is provided in areceiving groove 222 which is on a cylindrical portion 224 of theplunger 204. Both seals 216, 220 are preferably formed of a suitableelastomeric material. The plunger 204 also preferably includes a domedtop portion 226 and a flange 228. As will be described more fully laterhereinbelow, the plunger 204 is configured to traverse up and downrelative to the valve body 50 a, to facilitate venting and sealing,respectively, of the reaction chamber 48 in the cup 42.

The cap assembly 44 a also includes a spring-retaining member 230 whichis affixed to an inside, top surface 232 of the valve body 50 a, betweenthe valve body 50 a and the cap 108 a. Preferably, the spring-retainingmember 230 is a single piece, multi-walled structure. Thespring-retaining member 230 preferably includes inwardly-extendingflanges 234 which function as a plunger stop, via contact with theflange 228 on the plunger 204, as shown in FIG. 11. The spring-retainingmember 230 also includes apertures 236 for receiving a control spring238, and control spring supports 240. As shown in FIG. 12, preferablythe control spring 238 is a beam-like member having a generally U-shapedcross-section, and acts as a beam to transfer the pressure induced loadfrom the abutting plunger 204 to the control spring supports 240,thereby resisting upward movement of the plunger 204. While FIG. 12illustrates a specific control spring configuration, the control springmake take other forms. Regardless, the spring-retaining member 230retains the control spring 238 in its apertures 236, and the controlspring 238 works to effectively control the up and down movement of theplunger 204. Specifically, while the cylindrical portion 224 of theplunger 204 traverses in a plunger cylinder area 242 in the valve body50 a, the piston 208 traverses in a piston cylinder area 244 in thevalve body 50 a. Initially, the contact lens disinfecting system 40 aappears as shown in FIG. 10, with the plunger 204 in the down position.In the down position, the flange 228 of the plunger 204 contacts surface245 of the valve body 50 a, which restricts further downward travel ofthe plunger 204.

Much like as with the contact lens disinfecting system 40 shown in FIGS.7 and 8, the contact lens disinfection system 40 a shown in FIGS. 10 and11 provides that in use, approximately 10 milliliters of hydrogenperoxide solution 92 is poured into the cup 42, the retaining baskets 58on the stem 52 a are pivoted open, contact lenses are placed onto thestem 52 a, and then the retaining baskets 58 are pivoted closed in orderto retain the contact lenses in space 60. Finally, the stem 52 a isinserted into the cup 42, and the cap assembly 44 a is threaded onto thetop 46 of the cup 42. Preferably, the cup 42 is sized such that when thecap assembly 44 a is threaded onto the top 46 of the cup 42, with 10milliliters of hydrogen peroxide 92 being contained in the cup 42, thereremains 4 cc's of headspace 98 above the hydrogen peroxide 92, forcontainment of oxygen gas which evolves during the disinfection process.While providing 4 cc's of headspace is one possibility, the volume ofthe headspace 98 can be varied as can the surface area of the catalyst54, in order to achieve a desired internal pressure to control thereaction as previously discussed.

Once the catalyst 54 has been introduced to the hydrogen peroxidesolution 92, and the contact lens disinfecting system 40 a is sealed bythreading the cap assembly 44 a onto the top 46 of the cup 42, thesystem 40 a appears as shown in FIG. 10, and pressure in the reactionchamber 48 starts to increase. As pressure with the headspace 98 againstthe piston 208 continues to increase from the ongoing disproportionationand the plunger 204 traverses (upward) in response, the “U” shape of thecontrol spring 238 deforms in a manner in which the cross-sectionalheight of the “U” form becomes smaller and the beam strength of thecontrol spring 238 declines. When the combination of the force deliveredto the control spring 238 by the plunger 204 reaches the maximum beamstrength of the control spring 238, the control spring 238 flattens andbuckles, allowing the plunger 204 (and piston 208) to move upward untilthe flange 228 on the plunger 204 abuts the plunger stop 234, as shownin FIG. 11. In this deformed condition, the control spring 238 offersthe plunger 204 significantly lower resistance. Typical resistance tothe bending force offered by the control spring 238 can more clearly beunderstood by viewing FIG. 13. FIG. 13 is a graph which shows how thebeam strength of a spring, such as the control spring 238, changes basedon the amount of deflection. As shown in FIG. 13, the control spring 238demonstrates its maximum beam strength of 2.69 units when the plunger204 bearing upon it reaches 0.090 inches of travel and its minimum beamstrength of 0.64 units (or less than 25% of the maximum) at 0.105 inchesof plunger travel (i.e., just 0.025 inches later).

Movement of the plunger 204 upward to the plunger stop 234 allows theventing feature 212 on the piston 208 to pass beyond the piston seal216, thereby providing an avenue of escape for the pressurized oxygenwithin the headspace 98. Escaping oxygen flowing along venting feature212 is allowed to pass above the piston seal 216, flow into passage 200,and slowly escape along the close-fitting, but unsealed, interfacebetween the rim 246 of the cup 42 and the valve body 50 a, and betweenmating faces of threads 136, 138 provided on cup 42 and the cap assembly44 a, respectively. These unsealed interfaces allow gas flow into theambience and although inhibiting flow rate, impose no pressurelimitation upon the escaping gas. Gas pressure traveling along theventing feature 212 on the piston 208 also passes along the clearancebetween the piston 208 and the valve body 50 a, thereby impinging uponthe plunger seal 220. Because the plunger seal 220 is larger indiameter, force exerted by the plunger 204 against the plunger stop 234and the control spring 238 increases beyond that exerted by the piston208 and remains greater until the slowly dissipating gas pressure withinthe headspace 98 has reduced sufficiently for the control spring 238 toovercome the force of the plunger 204 and drive the plunger 204 downwardcausing the venting feature 212 on the piston 208 to pass below thepiston seal 216, as shown in FIG. 10, thereby terminating communicationbetween the headspace 98 and the ambience.

As shown in FIG. 14, applying the example of a spring (i.e., controlspring 238) functioning as shown in FIG. 13 and a receiving force fromthe piston 208 of a 0.0123 square inch area, allows a peak pressure of219 p.s.i. to be achieved within headspace 98 before the control spring238 deflects sufficiently to allow venting, as shown in FIG. 11. Aplunger seal 220 having twice the diameter of the piston 208 wouldpresent a 0.049 square inch surface area and provide sufficient force tokeep the control spring 238 deflected until residual pressure within theheadspace 98 drops to approximately 13 p.s.i, at which point the controlspring 238 straightens, pushing the plunger 204 (and piston 208) backdown, reseating it against surface 245, as shown in FIG. 10.

Following venting of headspace 98 as described above, activity of thepressure-inhibited catalytic reaction increases and then declines as theconversion of hydrogen peroxide into water and oxygen depletes theperoxide supply at a decreasing rate. Residual pressure after theplunger 204 and piston 208 have reseated (as shown in FIG. 10), combinedwith pressure resulting from the breakdown of remaining hydrogenperoxide, elevates the pressure within headspace 98 in a manner as shownin FIG. 14, as the disinfection process completes 6 to 8 hours afterstarting.

Much like the contact lens disinfecting system 40 shown in FIGS. 7 and8, the contact lens disinfecting system 40 a shown in FIGS. 10 and 11preferably provides that sufficient threads 136, 138 are provided on thecup 42 and the cap assembly 44 a, respectively, to allow the sealingmember 62 on the stem 52 a to pass a chamfer 140 which is provided atthe top 46 of the cup 42, in order to relieve any residual pressure thatmay be present prior to final unscrewing of the cap assembly 44 a fromthe cup 42. Conversely, during installation of the cap assembly 44 a,sufficient thread engagement is provided before the sealing member 62 onthe stem 52 a passes below the chamfer 140, in order to assure thatadequate structure is engaged for containment of pressure generatedduring disinfection.

FIGS. 15 and 16 are cross-sectional views of a contact lens disinfectingsystem 40 b which is in accordance with yet another embodiment of thepresent invention. The system 40 b is also configured to create thedesirable elevated pressure, oxygen saturation and sustained peroxideconcentration conditions within its contact lens holding and reactionchamber, in order to enhance disinfection by additive effect asdisclosed hereinabove. In many respects, the structure and operation ofthe contact lens disinfection system 40 b shown in FIGS. 15 and 16 issimilar to the contact lens disinfecting systems 40, 40 a previouslydescribed. As such, identical reference numerals are used to identifyidentical parts. For example, much like the contact lens disinfectingsystems 40, 40 a, the contact lens disinfection system 40 b includes acup 42 and a cap assembly 44 b which is configured to threadably engagethe top 46 of the cup 42, and the cup 42 is conventional in that it isgenerally cylindrical and provides a reaction chamber 48 therein fordisinfecting contact lenses.

The cap assembly 44 b comprises a cap 108 b which is affixed to a valvebody 50 b. The valve body 50 b is preferably a single piece,multi-walled structure and is configured to threadably engage the top 46of the cup 42. A stem 52 is attached to and hermetically sealed to thevalve body 50 b. A catalyst 54 (conventional with regard tocomposition), sized to complete the reaction within an appropriate time,is affixed to the bottom 56 of the stem 52. Additionally, contact lensretaining baskets 58 are disposed on the stem 52. The retaining baskets58 are configured to pivot open and closed, in order to receive contactlenses, and maintain the contact lenses in a space 60 which is providedbetween the stem 52 and the retaining baskets 58. A sealing member 62 isprovided on the stem 52, for sealing against an internal wall 64 of thecup 42.

Much like contact lens disinfecting system 40, contact lens disinfectingsystem 40 b provides that there is a passage 300 in the valve body 50 b,and that an aperture 302 leads to the passage 300, to provide a fluidpath for venting the reaction chamber 48. There is a plug 303 at the endof the passage 300, and the plug 303 seals the end of the passage aswell as provides a barrier to entrance of undesirable organisms afterthe peroxide solution 92 has been catalytically decomposed. The valvebody 50 b also has an additional aperture 304, i.e., an exhaust port,which allows venting gas to travel from the passage 300, to the rim 246of the cup 42, along the threads 136, 138 between the cup 42 and the capassembly 44 b, and out to the atmosphere. The plug 303 works to containthe pressure in the passage 300, limiting the escape of venting gas outthrough the exhaust port 304 and along the threads 136, 138.

Apertures 306 are provided on the valve body 50 b for retaining acontrol spring 238 proximate spring supports 308 (said control springpreferably being identical in nature to the control spring of the system40 a shown in FIGS. 10 and 11). The valve body 50 b includes a plungerreceptacle 310, and a plunger 312 is disposed in the plunger receptacle310. The plunger 312 can take many forms, but one preferred structure ofthe plunger 312 provides that the plunger 312 consists of a plastic bodyhaving a piston 314, formed of an elastomeric material, molded onto theplastic body to provide a plunger seal 324 and a piston seal 326.

The plunger 312 preferably has a domed-shaped top surface 318 and aflange 320. The plunger 312 is configured to traverse within thereceptacle 310 of the valve body 50 b, and the flange 320 is configuredto limit downward movement of the plunger 312 in the receptacle 310, viacontact between the flange 320 and surface 322 of the valve body 50 b asshown in FIG. 15.

The plunger 312 also defines a plunger seal 324, and a piston seal 326is provided on the piston 314. When the plunger 312 traverses in thereceptacle 310, the plunger seal 324 traverses relative to a plungercylinder area 328 of the receptacle 310, and the piston seal 326traverses relative to a piston cylinder area 330 of the receptacle 310.A transition area 332 is provided between the plunger cylinder area 328and the piston cylinder area 330, and the plunger 312 has a plunger stem334 which is located between the piston seal 326 and the plunger seal324. At the end 316 of the plunger 312 is a plunger guide 336, and theplunger guide 336 is configured to contact an internal wall 338 of thevalve body 50 b, in the piston cylinder area 330, and align the piston314.

Much like as with the contact lens disinfecting systems 40, 40 a, thecontact lens disinfection system 40 b shown in FIGS. 15 and 16 providesthat in use, approximately 10 milliliters of hydrogen peroxide solution92 is poured into the cup 42, the retaining baskets 58 on the stem 52are pivoted open, contact lenses are placed onto the stem 52, and thenthe retaining baskets 58 are pivoted closed in order to retain thecontact lenses in space 60. Finally, the stem 52 is inserted into thecup 42, and the cap assembly 44 b is threaded onto the top 46 of the cup42. Preferably, the cup 42 is sized such that when the cap assembly 44 bis threaded onto the top 46 of the cup 42, with 10 milliliters ofhydrogen peroxide 92 being contained in the cup 42, there remains 4 cc'sof headspace 98 above the hydrogen peroxide 92, for containment ofoxygen gas which evolves during the disinfection process. Whileproviding 4 cc's of headspace is one possibility, the volume of theheadspace 98 can be varied as can the surface area of the catalyst 54,in order to achieve a desired internal pressure to control the reactionas previously discussed.

Once the catalyst 54 has been introduced to the hydrogen peroxidesolution 92, and the contact lens disinfecting system 40 b is sealed bythreading the cap assembly 44 b onto the top 46 of the cup 42, thesystem 40 b appears as shown in FIG. 15, and pressure in the reactionchamber 48 starts to increase. From the starting position shown in FIG.15, longitudinal movement of the plunger 312 traversing within the valvebody 50 b is limited by the control spring 238, which is configured todetain the plunger's movement until pressure within headspace 98 entersthe piston cylinder area 330 and bears upon the piston 314 withsufficient force to exceed the beam strength of control spring 238 andthereby initiate its flattening and buckling. As this deformation of thecontrol spring 238 occurs, piston 314 exits piston cylinder area 330 andtraverses into the transition area 332. The plunger stem tip 334 remainsengaged with the internal wall 338 of the valve body 50 b in the pistoncylinder area 330 in order to stabilize the plunger 312.

Preferably, one or more flats 340 (or other structure) are provided onthe plunger stem tip 334, to allow for the flow of pressurized oxygenfrom headspace 98 to enter plunger cylinder area 328 through thetransition section 332, and bear next upon the larger diameter plungerseal 324 to provide additional force against control spring 238, therebyforcing it against a stop boss 342 (see FIG. 16) which is provided onthe underside of the cap 108 b. As the plunger seal 324 rises inresponse to the gas pressure it is receiving, it uncovers aperture 302,allowing gas under pressure to enter passageway 300 and communicate withexhaust port 304, positioned directly over the rim 246 of the cup 42.

Gas exiting the exhaust port 304 impinges upon and flows along theunsealed, closely-abutting surfaces of the rim 246 of the cup 42 and thevalve body 50 b, where it is distributed around the rim 246 of cup 42and subsequently flows to atmosphere along the mating clearance of thethreads 136, 138 into the ambiance. Although inhibiting flow rate, theseunsealed surfaces encountered by the escaping gas impose no pressurelimitation upon it. Once the pressure in the reaction chamber 48 hassufficiently decreased, as a result of venting, the control spring 238pushes the plunger 312 down and re-sets the system 40 b, as shown inFIG. 15.

Much like contact lens disinfecting systems 40, 40 a, the contact lensdisinfecting system 40 b shown in FIGS. 15 and 16 preferably providesthat sufficient threads 136, 138 are provided on the cup 42 and the capassembly 44 b, respectively, to allow the sealing member 62 on the stem52 to pass a chamfer 140 which is provided at the top 46 of the cup 42,in order to relieve any residual pressure that may be present prior tofinal unscrewing of the cap assembly 44 b from the cup 42. Conversely,during installation of the cap assembly 44 b, sufficient threadengagement is provided before the sealing member 62 on the stem 52passes below the chamfer 140, in order to assure that adequate structureis engaged for containment of pressure generated during disinfection.

FIGS. 17 and 18 are cross-sectional views of a contact lens disinfectingsystem 40 c which is in accordance with yet another embodiment of thepresent invention. The system 40 c is also configured to create thedesirable elevated pressure, oxygen saturation and sustained peroxideconcentration conditions within its contact lens holding and reactionchamber, in order to enhance disinfection by additive effect asdisclosed hereinabove. In many respects, the structure and operation ofthe contact lens disinfection system 40 c shown in FIGS. 17 and 18 issimilar to the contact lens disinfecting systems 40, 40 a and 40 bpreviously described. As such, identical reference numerals are used toidentify identical parts. For example, much like the contact lensdisinfecting systems 40, 40 a, 40 b the contact lens disinfection system40 c includes a cup 42 and a cap assembly 44 c which is configured tothreadably engage the top 46 of the cup 42, and the cup 42 isconventional in that it is generally cylindrical and provides a reactionchamber 48 therein for disinfecting contact lenses.

The cap assembly 44 c comprises a cap 400 which is affixed to a valvebody 50 c. The cap 400 has a post 402 which is disposed on an insidesurface 404 of the cap 400, and has a circumferential lip 406 whichtends to keep the cap 400 retained on the valve body 50 c.

The valve body 50 c is preferably a single piece, multi-walled structureand is configured to threadably engage the top 46 of the cup 42. A stem52 is attached to and hermetically sealed to the valve body 50 c. Acatalyst 54 (conventional with regard to composition), sized to completethe reaction within an appropriate time, is affixed to the bottom 56 ofthe stem 52.

Additionally, contact lens retaining baskets 58 are disposed on the stem52. The retaining baskets 58 are configured to pivot open and closed, inorder to receive contact lenses, and maintain the contact lenses in aspace 60 which is provided between the stem 52 and the retaining baskets58. A sealing member 62 is provided on the stem 52, for sealing againstan internal wall 64 of the cup 42.

Much like as with the contact lens disinfecting systems 40, 40 a, 40 bpreviously described, the contact lens disinfection system 40 c shown inFIGS. 17 and 18 provides that in use, approximately 10 milliliters ofhydrogen peroxide solution 92 is poured into the cup 42, the retainingbaskets 58 on the stem 52 are pivoted open, contact lenses are placedonto the stem 52, and then the retaining baskets 58 are pivoted closedin order to retain the contact lenses in space 60. Finally, the stem 52is inserted into the cup 42, and the cap assembly 44 c is threaded ontothe top 46 of the cup 42. Preferably, the cup 42 is sized such that whenthe cap assembly 44 c is threaded onto the top 46 of the cup 42, with 10milliliters of hydrogen peroxide 92 being contained in the cup 42, thereremains 4 cc's of headspace 98 above the hydrogen peroxide 92, forcontainment of oxygen gas which evolves during the disinfection process.While providing 4 cc's of headspace is one possibility, the volume ofthe headspace 98 can be varied as can the surface area of the catalyst54, in order to achieve a desired internal pressure to control thereaction as previously discussed.

The cap assembly 44 c includes a plunger 408, and a bottom part 410 ofthe plunger 408 defines a piston 412. The piston 412 may be generallycylindrical having a domed end surface 414. The piston 412 includes aventing feature 416, such as a longitudinal slot 418 along the piston412. While a longitudinal slot 418 is shown in FIGS. 17-20, the ventingfeature 416 may take other forms, such as a flat along the side of thepiston 412, or a reduced diameter section along the piston 412, forexample. Regardless, the venting feature 416 provides for communicationwith a vent port 420 and ultimately a passage 422 in the valve body 50 cfor venting the reaction chamber 48 along an opening 424 between the cap400 and the valve body 50 c, as will be described more fully laterhereinbelow.

A piston seal 426 is provided in a receiving groove 428 between the stem52 and the valve body 50 c, and a plunger seal 430 is provided in areceiving groove 432 which is on a cylindrical portion 434 of theplunger 408. Both seals 426, 430 are preferably formed of a suitableelastomeric material. The plunger 408 also preferably has a plunger cap436 disposed thereon, and the plunger cap 436 provides a domed topportion 438 and the plunger 408 provides a flange 440. The plunger 408also includes an upwardly-extending post 442 which is received in areceptacle 446 in the plunger cap 436, and a plunger cap spring 448 isdisposed in the receptacle 446. As will be described more fully laterhereinbelow, the plunger 408 is configured to traverse up and downrelative to the valve body 50 c, to facilitate venting and sealing,respectively, of the reaction chamber 48 in the cup 42.

As shown in FIGS. 17 and 18, preferably the upper surface 450 of thevalve body 50 c provides a castellated structure 452 which is configuredto mate with corresponding castellated structure 454 which is providedinside the cap 400. A spring-retaining member 456 is affixed to aninside, top surface 458 of the valve body 50 c, between the valve body50 c and the cap 400. Preferably, the spring-retaining member 456 is asingle piece, multi-walled structure. The spring-retaining member 456preferably includes inwardly-extending stops 460 which function as aplunger stop, via contact with the flange 440 on the plunger 408, asshown in FIG. 18. As shown in FIGS. 19 and 20, the spring-retainingmember 456 also includes apertures 462 for receiving a control spring464, control spring supports 466, and cap return spring structures 470,as will be described in more detail later hereinbelow. Thespring-retaining member 456 also includes deflectable latching members468 which are configured to spread apart and allow the plunger cap 436to pass (see FIG. 18).

The control spring 464 is preferably much like the control spring 238which is included in contact lens disinfecting systems 40 a and 40 b(see FIGS. 10-16, as well as the associated description hereinabove). Assuch, the control spring 464 is preferably a beam-like member having agenerally U-shaped cross-section, and acts as a beam to transfer thepressure induced load from the abutting plunger 408 to the controlspring supports 466, thereby resisting upward movement of the plunger408. The spring-retaining member 456 retains the control spring 464 inits apertures 462 (see FIGS. 19 and 20), and the control spring 464works to effectively control the up and down movement of the plunger408. Specifically, while the cylindrical portion 434 of the plunger 408traverses in a plunger cylinder area 472 in the valve body 50 c, thepiston 412 traverses in a piston cylinder area 474 in the valve body 50c. Initially, the contact lens disinfecting system 40 c appears as shownin FIG. 17, with the plunger 408 in the down position. In the downposition, the flange 440 of the plunger 408 contacts surface 476 of thevalve body 50 c, which restricts further downward travel of the plunger408.

As mentioned above, control spring 464 acts as a beam to transfer thepressure-induced load from abutting plunger 408 to control springsupports 466 (see FIGS. 17 and 19), thereby resisting upward movement ofthe plunger 408 (and plunger cap 436). As pressure within the headspace98 against piston 412 from the ongoing disproportionation rises to thedesirable 180 p.s.i. to 366 p.s.i., the plunger 408 (with plunger cap436) gains sufficient force to overcome control spring 464. In response,the “U” shape of control spring 464 begins to deform in a manner inwhich the cross-sectional height of the “U” form becomes smaller causingthe beam strength of control spring 464 to decline. When force deliveredby plunger 408 reaches the maximum beam strength of control spring 464,the spring 464 flattens and buckles as its cross-section diminishesthereby allowing plunger 408 (with piston 412 and plunger cap 436) tomove upward as shown in FIGS. 18 and 20 until flange 440 abuts plungerstops 460 affixed to valve body 50 c, arresting any further upwardmovement of plunger 408. In this deformed condition, control spring 464offers plunger 408 significantly lower resistance. A typical shapetransition in response to bending loads by a spring such as controlspring 464 illustrated in FIGS. 19 and 20 and the spring's resistanceforces during such a transition in shape can more clearly be understoodby viewing FIG. 13. The control spring 464 shown in FIGS. 17-20demonstrates its maximum beam strength of 2.69 units when the plunger408 bearing upon it reaches 0.090 inch of travel and its minimum beamstrength of 0.64 units, or less than 25% of the maximum, at 0.105 inchof plunger travel just 0.025 of an inch later. Movement of piston 412drives plunger 408 upward and flange 440 toward plunger stops 460allowing the leading edge of the venting feature 416 to pass beyondpiston seal 426, as shown in FIG. 18, thereby providing an avenue ofescape for the pressurized oxygen within the headspace 98 and initiatingdepressurization within the disinfection system 40 c (FIG. 21).Specifically, pressurized oxygen gas leaving headspace 98 and enteringplunger cylinder area 472 is stopped by plunger seal 430 and is thenforced to enter vent port 420 where it is directed into the ambiencethrough passageway 422 (and opening 424).

Coincident with the upward movement of plunger 408, as flange 440approaches stops 460, the upwardly driven plunger cap 436 forcesdeflectable latching members 468 to spread apart and allow plunger cap436 to bypass. When the latching members 468 then return to theiroriginal position, the plunger cap 436 becomes trapped above, as shownin FIG. 18, thereby retaining control spring 464 in its deflectedcondition (as shown in FIGS. 18 and 20). Plunger cap spring 448 thenprovides the only downward force against plunger 408. A small force fromthe plunger cap spring 448, in the range of 0.12 lb-0.50 lb in theimmediate example herein, is sufficient to drive plunger 408 (withpiston 412) back downward once pressure within headspace 98 hasdissipated to a range of 9.8 p.s.i. to 40 p.s.i., for example. Downwardmovement of piston 412 allows the leading edge of the venting feature416 to pass below piston seal 426 thereby terminating communicationbetween headspace 98 and the ambience, as shown in FIG. 17. Followingventing of headspace 98 as described above, activity of thepressure-inhibited catalytic reaction initially increases and thendecreases as the conversion of hydrogen peroxide into water and oxygendepletes the peroxide supply at a decreasing rate. As pressure withinheadspace 98 begins to climb in response to the invigorated catalyticreaction, pressure against piston 412 causes plunger 408 to compressplunger cap spring 448 sufficiently to allow enough movement for ventingfeature 416 to move past piston seal 426 and allow pressure to escapeheadspace 98. After pressure in headspace 98 has again vented off, forcefrom spring 464 bearing on plunger 408 pushes plunger 408 (and piston412) downward along piston seal 426, terminating flow through ventingfeature 416. This venting cycle of low pressure inspired opening andclosing continues, keeping pressure within headspace 98 low, limitingcommunication between headspace 98 and the ambience to an outward flowcondition while oxygen gas continues to be liberated throughdisproportionation of the hydrogen peroxide within cup 42 until anocularly safe peroxide concentration level has been reached after 6 to 8hours of reaction time.

Once the disinfection process has been completed, after 6 to 8 hours forexample, the freely rotating cap 400 retained to valve body 50 c by lip406, must be pressed downward in order to engage the castellatedstructure 452 on the cap 400 with corresponding castellated structure454 on the valve body 50 c, in order to allow unthreading of the capassembly 44 c from its threaded engagement with the top 46 of the cup42, for retrieval of the disinfected contact lenses. The act of pressingdown on the cap 400 also allows the post 402 in the cap 400 to deflectthe cap return spring structures 470, which extend from the controlspring supports 466, downward against control spring 464 which in turnpushes the plunger cap 436 against the latching members 468. This actioncauses the latching members 468 to deflect outward in response todownward pressure against the plunger cap 436, allowing passagetherethrough of the plunger cap 436, and further driving the plunger 408to its original seated position, as shown in FIG. 17, whereupon plungercap 436 again becomes captured by the now overhanging latching members468 as they spring back into place. The downward pressing actionrequired to remove the cap assembly 44 c from the top 46 of the cup 42and to replace it therefore serves to reset the pressure controlmechanism contained within in preparation for the next disinfectioncycle. Much like with the other systems 40, 40 a, 40 b previouslydescribed, preferably sufficient threads 478, 480 are provided on thecup 42 and the cap assembly 44 c, respectively, to allow the sealingmember 62 on the stem 52 to pass a chamfer 140 which is provided at thetop 46 of the cup 42, in order to relieve any residual pressure that maybe present prior to final unscrewing of the cap assembly 44 c from thecup 42. Conversely, during installation of the cap assembly 44 c,sufficient thread engagement is provided before the sealing member 62 onthe stem 52 passes below the chamfer 140, in order to assure thatadequate structure is engaged for containment of pressure generatedduring disinfection.

FIG. 21 is a graph which indicates how the pressure in the cup 42changes over time (depending on which size catalyst 54 is used, whereinthe curve identified with reference numeral 16 relates to the use of acatalyst having a given surface area, and the curve identified withreference numeral 18 relates to the use of a catalyst having twice thesurface area) when the disinfection system 40 c shown in FIGS. 17 and 18is employed. As shown in FIG. 21, the system 40 c provides that duringthe pressurization and decompression phases of the process includingventing to atmosphere, pressure within headspace 98 initially rises(i.e., to the high pressure level established by the control spring464), and then drops precipitously during venting after which it risesand falls slightly (i.e., as it responds to low pressure controlprovided by the interaction of plunger 408 and plunger cap spring 448).Concurrent with initial high pressure relief, the rate ofcatalytically-inspired disproportionation of hydrogen peroxide solution92 within the cup 42 increases beyond that just prior to pressure reliefas the activation energy level is lowered. Mixing currents are alsogenerated as oxygen boils from solution 92 and these resulting currentsinitially speed the catalytic decomposition by disturbing stratificationto bring more peroxide molecules into contact with the catalyst 54.Oxygen continues to evolve into the headspace 98 and is controlled bythe cyclic venting previously described as final decomposition of thesolution lowers peroxide concentration toward an ocularly safe level foruse of the lenses disinfected within.

FIGS. 22 and 23 are cross-sectional views of a contact lens disinfectingsystem 40 d which is in accordance with yet another embodiment of thepresent invention. The system 40 d is also configured to create thedesirable elevated pressure, oxygen saturation and sustained peroxideconcentration conditions within its contact lens holding and reactionchamber, in order to enhance disinfection by additive effect asdisclosed hereinabove. In many respects, the structure and operation ofthe contact lens disinfection system 40 d shown in FIGS. 22 and 23 issimilar to the contact lens disinfecting systems 40, 40 a, 40 b, 40 cpreviously described. As such, identical reference numerals are used toidentify identical parts. For example, much like the contact lensdisinfecting systems 40, 40 a, 40 b, 40 c, the contact lens disinfectionsystem 40 d includes a cup 42 and a cap assembly 44 d which isconfigured to threadably engage the top 46 of the cup 42, and the cup 42is conventional in that it is generally cylindrical and provides areaction chamber 48 therein for disinfecting contact lenses.

The cap assembly 44 d comprises a cap 108 d which is affixed to a valvebody 50 d. The valve body 50 d is preferably a single piece,multi-walled structure and is configured to threadably engage the top 46of the cup 42. A stem 52 is attached to and hermetically sealed to thevalve body 50 d. A catalyst 54 (conventional with regard tocomposition), sized to complete the reaction within an appropriate time,is affixed to the bottom 56 of the stem 52. Additionally, contact lensretaining baskets 58 are disposed on the stem 52. The retaining baskets58 are configured to pivot open and closed, in order to receive contactlenses, and maintain the contact lenses in a space 60 which is providedbetween the stem 52 and the retaining baskets 58. A sealing member 62 isprovided on the stem 52, for sealing against an internal wall 64 of thecup 42.

Apertures 506 are provided on the valve body 50 d for retaining acontrol spring 538 proximate spring supports 508 (said control spring538 preferably being identical in nature to the control spring 238 ofthe system 40 a shown in FIGS. 10 and 11 and previously described). Aswill be described more fully later hereinbelow, a plunger 512 isconfigured to traverse up and down relative to the valve body 50 d, andthe control spring 538 works to limit and control upward movement of aplunger 512 relative to the valve body 50 d.

The valve body 50 d includes a plunger receptacle 510, and the plunger512 is disposed in the plunger receptacle 510. The plunger 512preferably includes a domed-shaped top surface 518 which extends upwardfrom a generally cylindrical portion 519, and a stem portion 521 extendsdownward from the generally cylindrical portion 519. The plunger 512 cantake many forms, but one preferred structure of the plunger 512 providesthat the plunger 512 consists of a plastic body having a piston 514,formed of an elastomeric material, molded onto the plastic body toprovide a plunger seal 524 and a piston seal 526. While the plunger seal524 is provided on the generally cylindrical portion 519 of the plunger512, the piston seal 526 is provided on the stem portion 521 whichextends downward. While the piston seal 526 operates within and sealsagainst an internal wall 538 in a piston cylinder area 530 of the valvebody 50 d, the plunger seal 524 operates within and seals against aninternal wall 539 in a plunger cylinder area 528 of the valve body 50 d.A transition area 532 is provided between the plunger cylinder area 528and the piston cylinder area 530.

As discussed above, the plunger 512 is configured to traverse up anddown within the receptacle 510 of the valve body 50 d, and the controlspring 538 works to limit and control upward movement of the plunger 512relative to the valve body 50 d. With regard to downward movement of theplunger 512, a bottom surface 533 of the generally cylindrical portion519 of the plunger 512 is configured to limit downward movement of theplunger 512 in the receptacle 510, via contact with the internal wall535 of the valve body 50 b as shown in FIG. 22.

At the end 516 of the plunger 512 is a plunger guide 536, and theplunger guide 536 is configured to contact the internal wall 538 of thevalve body 50 d, in the piston cylinder area 530, and align the piston514. Preferably, one or more flats 540, and/or a vent notch 541 and/orother structure, are provided on the plunger guide 536, to allow for theflow of pressurized oxygen from headspace 98 to enter plunger cylinderarea 528 through the transition area 532, and bear next upon the largerdiameter plunger seal 524 to provide additional force against controlspring 538, thereby forcing it against a stop boss 542 (see FIG. 23)which is provided on the underside of the cap 108 d.

The contact lens disinfecting system 40 d includes a pressure controlvalve 570 which is comprised of a flapper valve 572, a post 574, and aplug 576 mounted to the valve body 50 d. As the piston seal 526 rises inresponse to the gas pressure it is receiving, it slides out of sealingengagement with internal wall 538 of the piston cylinder area 530, andenters transition area 532, thereby allowing gas in the headspace 98 tovent through the pressure control valve 570, and out a port 578 which isprovided in the plug 576. Specifically, the venting gas travels throughan opening 579 in the valve body 50 d, along port 578, and out a space560 which is provided between the cap 108 d and the valve body 50 d.Vent valves similar to the pressure control valve 570 have beenpreviously employed to facilitate venting of contact lens cases (seeU.S. Pat. No. 4,956,156).

From a downward starting position as shown in FIG. 22, upwardlongitudinal movement of plunger 512 traversing within valve body 50 dis limited by the control spring 538, which is configured to detain theplunger's movement until internal pressure reaches a certain point. Oncea high enough internal pressure (i.e., in headspace 98) is reached, theplunger 512 moves upward, resulting in the gas flowing past the plungerguide 536 (i.e., by means of the flats 540, vent notch 541, and/or otherstructure), and bearing upon the generally cylindrical portion 519 ofthe piston 514. The plunger 512, in turn, transfers the load to thecontrol spring 538 by means of the top surface 518 of the plunger 512bearing against the control spring 538. Just like the control spring238, the control spring 538 is “U”-shaped in cross-section and acts as abeam to transfer the pressure-induced load from abutting top surface 518to control spring supports 508, thereby resisting upward movement ofplunger 512.

As pressure within headspace 98 against piston 512 (from the ongoingdisproportionation of the solution 92) rises to the desirable 180 p.s.i.to 366 p.s.i. high pressure condition previously described, the plunger512 (with top surface 518) gains sufficient force to overcome controlspring 538. In response, the “U”-shape of the control spring 538 beginsto deform in a manner in which the cross-sectional height of the“U”-form becomes smaller, causing the beam strength of the controlspring 538 to decline. When the force delivered by the plunger 512 tothe control spring 538 reaches the maximum beam strength of controlspring 538, the spring 538 flattens and buckles as its cross-sectiondiminishes, thereby allowing plunger 512 (with piston 514 and topsurface 518) to move upward until the spring 538 abuts the stop 542 onthe cap 108 d, as shown in FIG. 23. In this deformed condition, thecontrol spring 538 offers plunger 514 significantly lower resistance. Atypical shape transition in response to bending loads by a spring suchas control spring 538 can be more clearly understood by comparing theshape of control spring 538 in FIG. 22 with its shape shown in FIG. 23,and the spring's resistance forces during such a transition in shape canmore clearly be understood by viewing FIG. 13. As shown in FIG. 13, aspring such as the control spring 538 shown in FIGS. 22 and 23demonstrates its maximum beam strength of 2.69 units when the plunger512 bearing upon it reaches 0.090 inch of travel and its minimum beamstrength of 0.64 units, or less than 25% of the maximum, at 0.105 inchof plunger travel just 0.025 of an inch later.

Decompression initiates as deformation of the control spring 538 allowsthe piston 514 to begin to exit the piston cylinder area 530 and enterthe transition area 532, thereby allowing pressurized oxygen bearing onthe piston 514 to enter the transition area 532. The plunger guide 536,having one or more vent flats 540, and/or vent notches 541 and/or otherstructure to allow gas flow to bypass, remains engaged with the internalwall 538 in the piston cylinder area 530 to stabilize the plunger 512 asit traverses upwards against the control spring 538. Oxygen gas underpressure flowing past piston 512 travels through the transition area532, enters the plunger cylinder area 528, and bears next upon thegenerally cylindrical portion 519 of the plunger 512 and its plungerseal 524, providing additional force against the control spring 538,pressing it against the stop 542 on the cap 108 d. If, for example, thepiston 514 were 0.125 inches in diameter, the force delivered by theplunger 512 to the control spring 538 in response to a headspacepressure of 220 p.s.i. would be 2.7 lbs. If, by further example, theplunger cylinder area 528 were 0.357 inches in diameter and gas at thesame pressure of 220 p.s.i. entered below the plunger seal 524, thepotential immediate force against the control spring 538 could increaseto 22 pounds. This increased force would only be momentary, however, dueto provision of the one way, low pressure, pressure-sensitive, pressurecontrol valve 570.

Gas entering the plunger cylinder area 528, and contained by the plungerseal 524, can only escape to the ambiance by means of pressure controlvalve 570. The flapper valve 572, retained on the post 574 by plug 576,communicates with the plunger cylinder area 528 through the opening 579which is provided in the valve body 50 d. Decompression of the headspace98 is precipitated as oxygen gas under pressure against flapper valve572 is allowed to vent at the annular junction between the flapper 572and the post 574, and exit to the ambiance through port 578 and outspace 560, once a threshold pressure of 20 p.s.i. to 32 p.s.i., forexample, has been reached. Such venting ceases as the flapper 572reseals against the post 574, after pressure against it has decreased toa level below that of the original threshold pressure, which for thisexample would be approximately 3 p.s.i. to 8 p.s.i. lower than thethreshold pressure. In the immediate example, a resealing pressure of 12p.s.i. bearing against plunger 512 would exert 1.2 pounds of forceagainst the control spring 538. This force would be adequate to holdcontrol spring 538 solidly against spring stop 542, as can be seen inFIG. 23, wherein control spring 538 requires only 0.66 pounds of forceto maintain its deflection of 0.11 inches and 0.81 pounds of force tomaintain its deflection of 0.15 inches. Pressure within headspace 98after initial venting fluctuates between the pressure control valve'svent pressure and its resealing pressure, but will not normally dropbelow its resealing pressure as decomposition of hydrogen peroxide 92continues to completion. Assuming the control spring 538 performs asshown in FIG. 13, if resealing pressure of the control valve 570 everdropped below 6.6 p.s.i., or in the event that flapper 572 failed toreseal to the post 574, control spring 538 would push the plunger 512downward, and the piston 514 would re-engage with the internal wall 538of the piston cylinder area 530, thereby sealing headspace 98 and thesolution 92 from communication with the ambiance to prevent any risk ofentry by foreign matter or organisms. In normal use, barring any failureof control valve 570, oxygen gas pressure within the headspace 98 wouldremain at a level between the pressure control valve's vent pressure andits resealing pressure, keeping plunger 512 upward and control spring538 deflected until cap 44 is unscrewed sufficiently to allow gas topass between sealing member 62 and chamfer 140 to relieve the pressure.

Much like as with the contact lens disinfecting systems 40, 40 a, 40 b,40 c, the contact lens disinfection system 40 d shown in FIGS. 22 and 23provides that in use, approximately 10 milliliters of hydrogen peroxidesolution 92 is poured into the cup 42, the retaining baskets 58 on thestem 52 are pivoted open, contact lenses are placed onto the stem 52,and then the retaining baskets 58 are pivoted closed in order to retainthe contact lenses in space 60. Finally, the stem 52 is inserted intothe cup 42, and the cap assembly 44 d is threaded onto the top 46 of thecup 42. Preferably, the cup 42 is sized such that when the cap assembly44 d is threaded onto the top 46 of the cup 42, with 10 milliliters ofhydrogen peroxide 92 being contained in the cup 42, there remains 4 cc'sof headspace 98 above the hydrogen peroxide 92, for containment ofoxygen gas which evolves during the disinfection process. Whileproviding 4 cc's of headspace is one possibility, the volume of theheadspace 98 can be varied as can the surface area of the catalyst 54,in order to achieve a desired internal pressure to control the reactionas previously discussed.

Once the catalyst 54 has been introduced to the hydrogen peroxidesolution 92, and the contact lens disinfecting system 40 d is sealed bythreading the cap assembly 44 d onto the top 46 of the cup 42, thesystem 40 d appears as shown in FIG. 22, and pressure in the reactionchamber 48 starts to increase. From the starting position shown in FIG.22, longitudinal movement of the plunger 512 traversing within the valvebody 50 d is limited by the control spring 538, which is configured todetain the plunger's movement until pressure within headspace 98 entersthe piston cylinder area 530 and bears upon the piston 514 withsufficient force to exceed the beam strength of control spring 538 andthereby initiate its flattening and buckling. As this deformation of thecontrol spring 538 occurs, piston 514 exits piston cylinder area 530 andtraverses into the transition area 532. The plunger guide 536 remainsengaged with the internal wall 538 of the valve body 50 d in the pistoncylinder area 530 in order to stabilize the plunger 512.

Much like contact lens disinfecting systems 40, 40 a, 40 b, 40 c, thecontact lens disinfecting system 40 d shown in FIGS. 21 and 22preferably provides that sufficient threads 136, 138 are provided on thecup 42 and the cap assembly 44 d, respectively, to allow the sealingmember 62 on the stem 52 to pass a chamfer 140 which is provided at thetop 46 of the cup 42, in order to relieve any residual pressure that maybe present prior to final unscrewing of the cap assembly 44 d from thecup 42. Conversely, during installation of the cap assembly 44 d,sufficient thread engagement is provided before the sealing member 62 onthe stem 52 passes below the chamfer 140, in order to assure thatadequate structure is engaged for containment of pressure generatedduring disinfection.

Decompression provides a further additive effect to the disinfectionprocess when oxygen occupying the headspace 98 is allowed to escape bymovement of the piston 514 and saturated oxygen within the hydrogenperoxide disinfection solution boils off, thereby allowing pressure inthe headspace 98 to drop to a point slightly above the atmosphericambient much more quickly than a pathogenic organism could adjust tomaintain dynamic equilibrium. During the pressurization anddecompression phases of the process, including venting to atmosphere,pressure within the headspace 98 initially rises to the high pressurelevel established by the control spring 538, and then precipitouslydrops during venting after which it rises and falls slightly, as shownin FIG. 24, as it responds to low pressure control provided by thereaction of the plunger 512 in response to the pressure control valve'sventing and resealing pressures. Concurrent with initial high pressurerelief, the rate of catalytically-inspired disproportionation of thehydrogen peroxide solution 92 increases beyond that just prior topressure relief as the activation energy level is lowered. Mixingcurrents are also generated as oxygen boils from the solution 92, andthese resulting currents initially speed the catalytic decomposition bydisturbing stratification to bring more peroxide molecules into contactwith the catalyst 54. Oxygen continues to be evolved into headspace 98and be controlled by the cyclic venting of the control valve 570 asfinal decomposition of the solution 92 lowers peroxide concentrationtoward an ocularly safe level for use of the lenses disinfected within.

FIGS. 25 and 26 are cross-sectional views of a contact lens disinfectingsystem 40 e which is in accordance with yet another embodiment of thepresent invention. The system 40 e is very much like the system 40 dshown in FIGS. 22 and 23, and includes a cap assembly 44 e that includesa cap 108 e which is affixed to a valve body 50 e, and there is acontrol valve 570 e on the valve body 50 e. The system 40 e includes aplunger 512 e and a piston 514 e is provided at the lower end of theplunger 512 e in the form of a downwardly-extending portion 521 e.However, unlike the system 40 d shown in FIGS. 22 and 23, the plungerseal 524 e of the system 40 e is provided in the form of a sealingmember 600 which is retained in a groove 602 on the generallycylindrical portion 519 e of the plunger 512 e, and the piston seal 526e is provided in the form of a sealing member 604 which is retained in areceiving groove 606 which provided between the valve body 50 e and thestem 52. Both sealing members 600, 604 are preferably formed of asuitable elastomeric material. A longitudinal slot 608, flat, reduceddiameter section, and/or other structure is provided on thedownwardly-extending portion 521 e of the plunger 512 e for allowing thepassage of gas from the headspace 98, as will be described more laterhereinblow.

Just like the system 40 d shown in FIGS. 22 and 23, the plunger 512 e ofthe system 40 e shown in FIGS. 25 and 26 can traverse up and downrelative to the valve body 50 e, and a U-shaped (in cross-section)control spring 538 e controls upward longitudinal movement of theplunger 512 e. The control spring 538 e of the system 40 e shown inFIGS. 25 and 26 is structured and acts much the same way as the other“U”-shaped control springs previously described. As such, FIG. 13 andthe descriptions hereinabove relating to such a spring are applicable.

In operation, once the catalyst 54 has been introduced to the hydrogenperoxide solution 92, and the contact lens disinfecting system 40 e issealed by threading the cap assembly 44 e onto the top 46 of the cup 42,the system 40 e appears as shown in FIG. 25, and pressure in thereaction chamber 48 starts to increase. From the starting position shownin FIG. 25, longitudinal movement of the plunger 512 e traversing withinthe valve body 50 e is limited by the control spring 538 e, which isconfigured to detain the plunger's movement until pressure withinheadspace 98 is sufficient to push up on the plunger 512 e such that theplunger 512 e moves upward (against the spring 538 e up to the stop 542e on the cap 108 e) and the slot 608, flat, reduced diameter section,and/or other structure slides up past the piston seal 526 e, as shown inFIG. 26. The gas in the headspace 98 then travels along the space 610which is provided between the piston 514 e and the internal wall 539 eof the piston cylinder area 530 e, enters the plunger cylinder area 528e, and is stopped by the plunger seal 524 e where the additional surfacearea of the plunger 512 e works to effectively increases the force thatthe top surface 518 e applies against the control spring 538 e.

Much like with the system 40 d, the system 40 e shown in FIGS. 25 and 26provides that if, for example, the piston 514 e were 0.125 inches indiameter, the top surface 518 e of the plunger 512 e would exert abending force against the control spring 538 e of 2.7 lbs once 220p.s.i. of pressure is reached within headspace 98. By comparison, theplunger 512 e at 0.357 inches in diameter would have the potential toexert 22 lbs of force against the control spring 538 e when exposed to220 p.s.i. of pressure. This increased force would only be momentary,however, due to provision of the one way, low pressure,pressure-sensitive, pressure control valve 570 e.

Gas entering the plunger cylinder area 528 e, and contained by theplunger seal 524 e, can only escape to the ambiance by means of pressurecontrol valve 570 e, as described above in connection with the system 40d shown in FIGS. 22 and 23. At 12 p.s.i., the force exerted by theplunger 512 e would be sufficient to keep the spring 538 e deflected andmaintain communication between the headspace 98 and the control valve570 e.

As disclosed above with regard to the system 40 d, the system 40 e shownin FIGS. 25 and 26 provides that pressure initially rises to the highpressure established by the control spring 538 e, and then dropsprecipitously during venting after which the pressure rises and fallsslightly, as shown in FIG. 24, as it responds to low pressure controlprovided by the control valve 570 e. After initial venting, pressurewithin the headspace 98 fluctuates between the pressure control valve'svent pressure and its resealing pressure, but does not normally dropbelow its resealing pressure. This low level rising and falling pressurepattern continues for several hours after decompression as decompositionof the hydrogen peroxide 92 continues to a lower concentration level,down to an ocularly safe level.

Assuming the control spring 538 e performs as shown in FIG. 13, ifresealing pressure of the control valve 570 e ever dropped below 6.4p.s.i., or in the event that the control valve 570 e failed to reseal,control spring 538 e would push the plunger 512 e downward, causing thelongitudinal slot 608, flat, reduced diameter section, and/or otherstructure on the plunger 512 e to drop below the piston seal 526 e, asshown in FIG. 25, thereby effectively sealing the headspace 98 andsolution 92 from communication with the ambience and preventing any riskof entry by foreign matter or organisms.

As with the other systems 40, 40 a, 40 b, 40 c, 40 d, the system 40 eshown in FIGS. 25 and 26 provides that sufficient threads 136, 138 areon the cup 42 and the cap assembly 44 e, respectively, to allow thesealing member 62 on the stem 52 to pass a chamfer 140 which is providedat the top 46 of the cup 42, in order to relieve any residual pressurethat may be present prior to final unscrewing of the cap assembly 44 efrom the cup 42. Conversely, during installation of the cap assembly 44e, sufficient thread engagement is provided before the sealing member 62on the stem 52 passes below the chamfer 140, in order to assure thatadequate structure is engaged for containment of pressure generatedduring disinfection.

As with the other systems 40, 40 a, 40 b, 40 c, 40 d, the system 40 eshown in FIGS. 25 and 26 provides that decompression resulting from therelease of high pressure within the system 40 e provides a furtheradditive effect to the disinfection process by creating additionalstress against the cell membranes of pathogenic organisms undergoingdenaturation previously discussed hereinabove.

Each of the systems 40, 40 a, 40 b, 40 c, 40 d, 40 e describedhereinabove provides that decompression resulting from release of highpressure within the system provides a further additive effect to thedisinfection process when oxygen occupying headspace 98 is allowed toescape in a controlled manner and saturated oxygen within the hydrogenperoxide disinfection solution boils off thereby allowing pressure inheadspace 98 to drop to the controlled low pressure level much morequickly than a pathogenic organism could adjust in order to maintaindynamic equilibrium.

It should be pointed out that any of the systems 40, 40 a, 40 b, 40 c,40 d, 40 e described hereinabove can be redesigned to include adiaphragm. FIGS. 27 and 28 illustrate an example wherein the systems 40d, 40 e shown in FIGS. 22, 23, 25 and 26 have been redesigned in thisfashion. As shown in FIGS. 27 and 28, the system 40 f includes adiaphragm 700 located in a diaphragm chamber 701, in the form of anelastomeric member which is held in place between a valve body 50 f anda spring-retaining member 702. As shown, preferably the spring-retainingmember 702 includes a shoulder 703 which tends to keep the diaphragm 700retained. A portion 704 of the diaphragm 700 is engaged with anextending portion 706 of a plunger 708. The plunger 708 is moveable upand down, generally into and out of, a plunger-receiving receptacle 710of the valve body 50 f. When the plunger 708 is in a first position, asshown in FIG. 27, wherein the extending portion 706 of the plunger 708is seated in the plunger-receiving receptacle 710, there is no ventingof the system 40 f through the pressure control valve 570 f. In thisposition, the diaphragm 700 seals with an internal shoulder 712 on thevalve body 50 f, and the pressure within the headspace 98 is allowed toincrease while the solution 92 reacts to the catalyst 54. However, oncepressure in the system 40 f increases to a sufficiently high enoughpressure, the pressure in the headspace 98 pushes the plunger 708 upinto the position shown in FIG. 28. In this position, the diaphragmchamber 701 is no longer sealed from headspace 98 with the internalshoulder 712 on the valve body 50 f, and the system 40 f is allowed tovent along a space 714 provided between the diaphragm 700 and the valvebody 50 f, into diaphragm chamber 701, and out the pressure controlvalve 570 f along interface 716 between the valve body 50 f and the topof the cup 42. Other the difference of using a diaphragm to effectivelytake the place of the plunger having an over-molded surface, the system40 f is structured and operates similar to both systems 40 d and 40 e.As such, the system 40 f includes, for example, a cap 108 f having astop 742 f as well as includes a U-Shaped control spring 738 which isidentical to the control spring 238 shown on FIG. 12 and described atlength above in connection with other embodiments.

While specific embodiments of the present invention are shown anddescribed, it is envisioned that those skilled in the art may devisevarious modifications of the present invention without departing fromthe spirit and scope of the present invention.

1. A disinfecting system for using solution and a catalyst to disinfectan object, said disinfecting system comprising: a cup configured toretain the solution therein; and a cap assembly engageable with the cupand configured to retain the object as well as the catalyst, said capassembly comprising a member which is shiftable between a first positionfor sealing the disinfecting system and a second position for ventingthe disinfecting system, and a control spring in contact with theshiftable member when the shiftable member is in the second position andconfigured to bias the shiftable member from the second position to thefirst position, wherein the disinfecting system is configured such thatpressure within the disinfecting system increases as a result of thesolution reacting to the catalyst, during which time additive effectenhances the disinfection of the object, and during which time theshiftable member is in said first position, wherein the disinfectingsystem is configured such that pressure within the disinfecting systemfurther increases, thereby causing the shiftable member to shift fromthe first position to the second position, thereby causing venting ofthe disinfecting system, and wherein the disinfecting system isconfigured such that pressure within the disinfecting system decreasesduring venting, thereby causing the control spring to push the shiftablemember from the second position to the first position, thereby causingresealing of the disinfecting system.
 2. A disinfecting system asrecited in claim 1, wherein the control spring has a U-shaped crosssection.
 3. A disinfecting system as recited in claim 1, wherein the capassembly further comprises a valve body which is configured to engage atop of the cup.
 4. A disinfecting system as recited in claim 3, whereinthe cap assembly further comprises a spring-retaining member whichretains said control spring and is affixed to said valve body.
 5. Adisinfecting system as recited in claim 1, wherein the shiftable memberincludes a venting feature.
 6. A disinfecting system as recited in claim1, wherein the cap assembly further comprises a valve body which isconfigured to engage a top of the cup and a stem which is engaged withthe valve body, wherein a sealing member is disposed between the stemand the valve body, wherein the shiftable member includes a ventingfeature, and wherein the venting feature passes said sealing member assaid shiftable member shifts from the first position to the secondposition, thereby allowing venting of the system.
 7. A disinfectingsystem as recited in claim 6, wherein a vent passage is provided betweensaid stem and said valve body, wherein the venting feature on theshiftable member passes said sealing member as said shiftable membershifts from said first position to said second position, therebyallowing venting of the system along said vent passage.
 8. Adisinfecting system as recited in claim 1, wherein the cap assemblyfurther comprises a valve body which is configured to engage a top ofthe cup and a stem which is engaged with the valve body, wherein a firstsealing member is disposed between the stem and the valve body, whereinthe shiftable member includes a venting feature, wherein the ventingfeature on the shiftable member passes said sealing member as saidshiftable member shifts between said first and second positions, whereina second sealing member is disposed on the shiftable member and sealsagainst the valve body.
 9. A disinfecting system as recited in claim 8,wherein a vent passage is provided between said stem and said valvebody, wherein the venting feature passes said first sealing member assaid shiftable member shifts from the first position to the secondposition, thereby allowing venting of the system along said ventpassage.
 10. A disinfecting system as recited in claim 3, wherein saidvalve body is configured to contact and restrict further movement of theshiftable member in the first position.
 11. A disinfecting system asrecited in claim 4, wherein said valve body is configured to contact andrestrict further movement of the shiftable member in the first position,and wherein the spring-retaining member is configured to contact andrestrict further movement of the shiftable member in the secondposition.
 12. A disinfecting system as recited in claim 1, wherein thecap assembly further comprises a valve body which is configured toengage a top of the cup, wherein the shiftable member comprises aplurality of seals which contact and seal with the valve body, whereinwhen said shiftable member shifts from the first position to the secondposition at least one of the seals slides out of contact with the valvebody, thereby allowing venting of the system through a vent passageprovided in the valve body.
 13. A disinfecting system as recited inclaim 12, further comprising a plug at the end of the vent passage forsealing the end of the passage and providing a barrier of entry into thesystem.
 14. A disinfecting system as recited in claim 1, wherein the capassembly further comprises a valve body which is configured to engage atop of the cup, wherein the shiftable member comprises a first sealwhich contacts and seals with the valve body, wherein the shiftablemember comprises a second seal which contacts and seals with the valvebody, wherein when said shiftable member shifts from the first positionto the second position, the first seal slides out of contact with thevalve body, thereby allowing venting of the system through a ventpassage provided in the valve body, but said second seal slides alongsaid valve body and remains in sealing contact therewith.
 15. Adisinfecting system as recited in claim 14, wherein the second seal isdisposed between the vent passage and the first seal when said shiftablemember is in said first position.
 16. A disinfecting system as recitedin claim 14, wherein the vent passage is disposed between the first sealand the second seal when said shiftable member is in said secondposition.
 17. A disinfecting system as recited in claim 14, wherein thesecond seal is disposed between the vent passage and the first seal whensaid shiftable member is in said first position, and wherein the ventpassage is disposed between the first seal and the second seal when saidshiftable member is in said second position.
 18. A disinfecting systemas recited in claim 14, wherein the valve body comprises an exhaust portwhich is in communication with the vent passage, wherein gas which ventsfrom the system travels along the vent passage, through the exhaustport, to a rim of the cup, and between the cup and the cap assembly. 19.A disinfecting system as recited in claim 1, wherein the shiftablemember comprises a plastic part having an elastomeric member thereon.20. A disinfecting system as recited in claim 1, wherein the shiftablemember has a dome-shaped top surface which contacts the control spring.